The Steam Page for BioShock Infinite is now accepting pre-purchases of Irrational Games' upcoming first-person shooter sequel. This does not include a discount, but includes three reward tiers that will unlock as more customers make an advance commitment. The first tier is already unlocked, so this offer now includes a free copy of the original BioShock. The second tier, currently one percent complete, will add exclusive BioShock Infinite Team Fortress 2 items, and the third tier will add a free copy of X-Com: Enemy Unknown. Those who already own one or both of the bonus games can gift them to friends through Steam.